DEFINITION:DEFINITION:Any type of device

used for stabilization or retention of

prosthesis -- GPT

RETAINERS

Retainer for an FPD…Retainer for an FPD… That component of an FPD That component of an FPD

which takes support from the which takes support from the abutment tooth and provides abutment tooth and provides retention to the prosthesisretention to the prosthesis

SELECTION OF RETAINERSSELECTION OF RETAINERS Retainer selection for abutment is Retainer selection for abutment is

critical and is dictated by the critical and is dictated by the followings:followings:

1)1) AgeAge2)2) DMF rateDMF rate3)3) Edentulous space-Partial veneer crown Edentulous space-Partial veneer crown

contraindicated in long span FPDcontraindicated in long span FPD4)4) Periodontal supportPeriodontal support5)5) Arch position of the toothArch position of the tooth6)6) Skeletal relationship Skeletal relationship

7)7) Inter occlusal & intraocclusal Inter occlusal & intraocclusal condition such as crown lengthcondition such as crown length

8)8) Oral hygiene of the patientOral hygiene of the patient

9)9) Vitality of the abutment teeth---Vitality of the abutment teeth---endodontically treated teeth may endodontically treated teeth may have to be restored with core & have to be restored with core & post before designing the retainerpost before designing the retainer

10)10) Condition of the abutment teethCondition of the abutment teeth

11)11) CostCost

12)12) Preservation of the tooth Preservation of the tooth structure----Buccal surface should be structure----Buccal surface should be conserved. Partial veneer crown is conserved. Partial veneer crown is more conservative than full crown . more conservative than full crown . All ceramic crowns are least All ceramic crowns are least conservativeconservative

Types of retainersTypes of retainers Classified as:Classified as:

I.I. Based on tooth coverageBased on tooth coverage Full veneer crownFull veneer crown

Partial veneer crownPartial veneer crown

Conservative (minimal prep.) Conservative (minimal prep.) retainersretainers

II.II. Based on material usedBased on material usedAll metal retainersAll metal retainers

Metal ceramic retainersMetal ceramic retainers

All ceramic retainersAll ceramic retainers

All acrylic retainersAll acrylic retainers

Full veneer Full veneer crownscrowns

Covers all 5 surfaces of abutmentCovers all 5 surfaces of abutment Most retentive of the veneer Most retentive of the veneer

preparationspreparations Compared to partial veneer Compared to partial veneer

designs,full veneer crown exhibits designs,full veneer crown exhibits superior resistance nd retentionsuperior resistance nd retention

Used on those teeth whose Used on those teeth whose restoration demands max. retention.restoration demands max. retention.

Variations—Metal ceramic crowns and Variations—Metal ceramic crowns and all ceramic crowns used in situations all ceramic crowns used in situations that requires a good cosmetic resultsthat requires a good cosmetic results

The full veneer crown should be used The full veneer crown should be used when less extensive and less when less extensive and less destructive design have been destructive design have been considered and found lacking in considered and found lacking in retention ,resistance ,coverage or retention ,resistance ,coverage or esthetics to properly restore the toothesthetics to properly restore the tooth

Partial veneer Partial veneer crowncrown

Preferred than full veneer crown because Preferred than full veneer crown because they requires less tooth reductionthey requires less tooth reduction

Crown does not cover the entire abutmentCrown does not cover the entire abutment Facial surface is left intact for superior Facial surface is left intact for superior

estheticsesthetics Used when minimal retention is sufficient Used when minimal retention is sufficient

and when abutment tooth is healthyand when abutment tooth is healthy

Contra indicationsContra indications

In long span FPDsIn long span FPDs Endodontically treated toothEndodontically treated tooth Dentition with active caries or Dentition with active caries or

periodontal diseaseperiodontal disease Poorly aligned abutment toothPoorly aligned abutment tooth

AdvantagesAdvantages

Conservation of tooth structureConservation of tooth structure Reduced pulpal and periodontal Reduced pulpal and periodontal

insult during tooth prepinsult during tooth prep Improved access for finishing by Improved access for finishing by

dentist & oral hygiene by patientdentist & oral hygiene by patient

Less of margin approximate soft Less of margin approximate soft tissues subgingivally and hence less tissues subgingivally and hence less gingival involvement than complete gingival involvement than complete coveragecoverage

Remaining intact facial or buccal Remaining intact facial or buccal tooth surface permits electric vitality tooth surface permits electric vitality testtest

DisadvantagesDisadvantages Less retention & resistance than Less retention & resistance than

complete crownscomplete crowns Some metal displayed in completed Some metal displayed in completed

restoration—unaestheticrestoration—unaesthetic Tooth prep is difficult because only Tooth prep is difficult because only

limitedlimited

adjustments can be made in the path adjustments can be made in the path of placementof placement

Resin bonded retainersResin bonded retainers(Maryland bridges)(Maryland bridges)

Require minimal tooth Require minimal tooth preparationpreparation

Acid etchedAcid etched Esthetically appealingEsthetically appealing Economical , conservative , Economical , conservative ,

functional & do not irritate soft or functional & do not irritate soft or hard tissueshard tissues

IndicationIndication

As retainers of FPD for abutment As retainers of FPD for abutment with sufficient enamel to etchwith sufficient enamel to etch

Splinting of periodontally Splinting of periodontally compromised teethcompromised teeth

Stabilizing dentition after Stabilizing dentition after orthodontic treatmentorthodontic treatment

ContraindicationContraindication In patients with sensitivity to base In patients with sensitivity to base

metal alloysmetal alloys When facial esthetic of abutment When facial esthetic of abutment

require improvementrequire improvement Inadequate enamel surface to bond Inadequate enamel surface to bond

eg;caries,existing restorationeg;caries,existing restoration Incisor with extremely thin facio-Incisor with extremely thin facio-

lingual dimensionlingual dimension

AdvantagesAdvantages Non invasive to dentin with lingual and Non invasive to dentin with lingual and

proximal tooth preparation including proximal tooth preparation including occlusal restocclusal rest

Conservative with undeniable patient Conservative with undeniable patient appearanceappearance

Tissue tolerant because of Tissue tolerant because of Supragingival margin,without pulpal Supragingival margin,without pulpal irritationirritation

Reduced cost and less chair side timeReduced cost and less chair side time

DisadvantageDisadvantage Demanding technique and tooth Demanding technique and tooth

prep.prep. Plaque accumulationPlaque accumulation Bulky contourBulky contour Restricted to single pontic placementRestricted to single pontic placement Graying out of teeth that are thin Graying out of teeth that are thin

labiolinguallylabiolingually

Based on material usedBased on material used

All metal retainers All metal retainers Metal ceramic retainersMetal ceramic retainers All ceramic retainersAll ceramic retainers

All metal retainersAll metal retainers

Partial or full veneer crownPartial or full veneer crown Require minimal tooth Require minimal tooth

reductionreduction Strong even in thin Strong even in thin

sectionssections

Metal ceramic retainersMetal ceramic retainers

Indicated on teeth that require Indicated on teeth that require complete coverage & esthetic complete coverage & esthetic demanddemand

Can accommodate cast or Can accommodate cast or soldered connectorssoldered connectors

Can afford high force—metalCan afford high force—metal Require more teeth reductionRequire more teeth reduction

IndicationIndication

Extensive tooth destruction as a Extensive tooth destruction as a result of caries or traumaresult of caries or trauma

Existing previous restoration that Existing previous restoration that precludes the use of a more precludes the use of a more conservative restorationconservative restoration

Need for superior retention and Need for superior retention and strengthstrength

Endodontically treated toothEndodontically treated tooth

ContraindicationContraindication

Whenever a more Whenever a more conservative retainer conservative retainer is feasibleis feasible

All ceramicAll ceramic Primary purpose ---to achieve Primary purpose ---to achieve

best possible esthetic resultsbest possible esthetic results Risk of reduced restoration Risk of reduced restoration

longevity—potential for longevity—potential for fracture ,inferior marginal fracture ,inferior marginal adaptation than PFM retaineradaptation than PFM retainer

Telescopic Telescopic retainersretainers

Used when path of insertion of FPD does Used when path of insertion of FPD does not coincide with long axis of abutmentnot coincide with long axis of abutment

Design involves fabricatin of two copings Design involves fabricatin of two copings one over the otherone over the other

Internal or primary coping function to Internal or primary coping function to modify the morphology of tooth –path pf modify the morphology of tooth –path pf insrtn changedinsrtn changed

Secondary coping designed to fit over Secondary coping designed to fit over primary primary

REFERENCESREFERENCES

1.1. Fundamentals of Fixed ProsthodonticsFundamentals of Fixed Prosthodontics Herber T.ShillingburgHerber T.Shillingburg2.2. Contemporary Fixed ProsthodonticsContemporary Fixed Prosthodontics Rosenstiel,Land,FujimotoRosenstiel,Land,Fujimoto3.3. Tylmans Theory and Practice of Fixed Tylmans Theory and Practice of Fixed

ProsthodonticsProsthodontics4.4. Textbook of Prosthodontics-Deepak Textbook of Prosthodontics-Deepak

NallaswamyNallaswamy

Thanking you…..Thanking you…..